Fluid dynamic mechanisms and interactions within separated flows

The component mechanisms and interactions which establish and maintain high-speed separated flow regions are discussed. Flow models and theoretical analyses have been developed to describe the base flowfield. The research approach has been to conduct extensive small-scale experiments on base flow configurations and to analyze these flows by component models and finite-difference techniques. Modeling of base flow of missiles (both unpowered and powered) for the transonic flight regime has been successful by component models based on the equivalent body approach. Development and use of a state-of-the-art laser Doppler velocimeter system for experiments with two-dimensional small-scale models in supersonic flows have provided quality, well-documented velocity data. The LDV experiments yielded mean and turbulence information for a variety of near-wake flow mechanisms such as initial shear layer development, recompression/reattachment/redevelopment processes, shock wave-boundary layer interactions, and propulsive jet/freestream interactions. Correlation between the LDV data and component method mixing analysis has yielded results of interest. Research on plume effects and plume modeling has defined the pertinent variables for effective wind tunnel simulation of propulsive nozzle plumes.